feat(mail): make notification failures non-fatal

Add App\Support\SafeNotifier that wraps $notifiable->notify() in a
Throwable guard with a logged warning, so SMTP outages (the current
Gmail 535 errors) no longer propagate as a 500 to the user. Apply to
the two hot paths that were still unprotected: CommentController
(new comment, reply, like) and RegisteredUserController (super-admin
registration alert). User::sendEmailVerificationNotification() is
wrapped inline for the same reason.

Also add docs/mail-setup.md covering the three delivery options:
Gmail app password (quick), Mailgun, Postmark — with the exact .env
keys for each.

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>

app/Http/Controllers/Auth/RegisteredUserController.php

@@ -7,6 +7,7 @@ use App\Models\User;
 use App\Notifications\NewUserRegistered;
 use App\Rules\NotDisposableEmail;
 use App\Rules\ReservedIdentifier;
+use App\Support\SafeNotifier;
 use Illuminate\Auth\Events\Registered;
 use Illuminate\Http\Request;
 use Illuminate\Support\Facades\Hash;
@@ -49,7 +50,7 @@ class RegisteredUserController extends Controller
 
         // Notify all super admins of the new registration
         User::where('role', 'super_admin')->each(function (User $admin) use ($user) {
-            $admin->notify(new NewUserRegistered($user));
+            SafeNotifier::send($admin, new NewUserRegistered($user));
         });
 
         auth()->login($user);

app/Http/Controllers/CommentController.php

@@ -9,6 +9,7 @@ use App\Notifications\NewCommentLikeNotification;
 use App\Notifications\NewCommentNotification;
 use App\Notifications\NewReplyNotification;
 use App\Services\LlmLyricsService;
+use App\Support\SafeNotifier;
 use Illuminate\Http\Request;
 use Illuminate\Support\Facades\Auth;
 
@@ -71,12 +72,12 @@ class CommentController extends Controller
             // Reply — notify the parent comment's author
             $parent = Comment::find($request->parent_id);
             if ($parent && $parent->user_id !== $commenter->id) {
-                $parent->user->notify(new NewReplyNotification($video, $comment, $commenter));
+                SafeNotifier::send($parent->user, new NewReplyNotification($video, $comment, $commenter));
             }
         } else {
             // Top-level comment — notify the video owner
             if ($video->user_id !== $commenter->id) {
-                $video->user->notify(new NewCommentNotification($video, $comment, $commenter));
+                SafeNotifier::send($video->user, new NewCommentNotification($video, $comment, $commenter));
             }
         }
 
@@ -162,7 +163,8 @@ class CommentController extends Controller
             if ($comment->user_id !== $userId) {
                 $video = $comment->video;
                 if ($video) {
-                    $comment->user->notify(
+                    SafeNotifier::send(
+                        $comment->user,
                         new NewCommentLikeNotification($video, $comment, Auth::user())
                     );
                 }

app/Models/User.php

@@ -281,7 +281,19 @@ class User extends Authenticatable implements MustVerifyEmail
 
     public function sendEmailVerificationNotification(): void
     {
-        $this->notify(new VerifyEmail);
+        // Mail failures must never bubble up as a 500 to the user — the account
+        // exists, the HTTP request was fine, only the delivery pipe is broken.
+        // We log the failure (ops picks it up) and move on. Re-sending via
+        // `php artisan app:resend-verification` fixes the user once SMTP recovers.
+        try {
+            $this->notify(new VerifyEmail);
+        } catch (\Throwable $e) {
+            \Illuminate\Support\Facades\Log::warning('verify-email send failed', [
+                'user_id' => $this->id,
+                'email'   => $this->email,
+                'error'   => $e->getMessage(),
+            ]);
+        }
     }
 
     // Role helper methods

app/Support/SafeNotifier.php

@@ -0,0 +1,43 @@
+<?php
+
+namespace App\Support;
+
+use Illuminate\Notifications\Notification;
+use Illuminate\Support\Facades\Log;
+
+/**
+ * Notification failures (SMTP down, Gmail 535, Mailgun 4xx, etc.) must never
+ * crash a user-facing request. Everywhere we previously did
+ *
+ *     $user->notify(new SomeNotification(...));
+ *
+ * we now do
+ *
+ *     SafeNotifier::send($user, new SomeNotification(...));
+ *
+ * which runs the same code, catches any Throwable, and writes a warning line
+ * so ops still has the signal.
+ */
+class SafeNotifier
+{
+    /**
+     * @param mixed $notifiable  Anything with ->notify(), usually a User.
+     */
+    public static function send(mixed $notifiable, Notification $notification): void
+    {
+        if (! $notifiable || ! is_object($notifiable) || ! method_exists($notifiable, 'notify')) {
+            return;
+        }
+
+        try {
+            $notifiable->notify($notification);
+        } catch (\Throwable $e) {
+            Log::warning('notification send failed', [
+                'notification' => $notification::class,
+                'notifiable'   => $notifiable::class,
+                'notifiable_id'=> $notifiable->getKey() ?? null,
+                'error'        => $e->getMessage(),
+            ]);
+        }
+    }
+}